Results 1 to 2 of 2

Math Help - keep having trouble with this..

  1. #1
    Junior Member
    Joined
    Oct 2009
    Posts
    34

    keep having trouble with this..

    Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis.

    y=20x5x^2
    y=0


    about the y-axis.


    How I started the problem was I solved the first equation and got [0,4]. And then I used these numbers and plugged it into the shell method.
    The equation that I used for the shell method was the first one equation that I listed.


    My answer was 853.33pi.


    But, it's incorrect. Can someone show me how to setup and solve the problem?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,040
    Thanks
    884
    Quote Originally Posted by abilitiesz View Post
    Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis.

    y=20x5x^2
    y=0


    about the y-axis.


    How I started the problem was I solved the first equation and got [0,4]. And then I used these numbers and plugged it into the shell method.
    The equation that I used for the shell method was the first one equation that I listed.


    My answer was 853.33pi.


    But, it's incorrect. Can someone show me how to setup and solve the problem?
    cylindrical shells ...

    V = 2\pi \int_0^4 x(20x-5x^2) \, dx = \frac{640\pi}{3}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Car trouble
    Posted in the Advanced Applied Math Forum
    Replies: 1
    Last Post: November 26th 2008, 03:53 PM
  2. So I'm having some trouble...
    Posted in the Calculus Forum
    Replies: 44
    Last Post: August 4th 2008, 11:03 PM
  3. im having trouble with this one.
    Posted in the Calculus Forum
    Replies: 2
    Last Post: April 4th 2008, 11:15 AM
  4. Replies: 5
    Last Post: April 3rd 2008, 02:19 PM
  5. Im having trouble with these
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: May 13th 2005, 12:43 PM

Search Tags


/mathhelpforum @mathhelpforum